Inconsistent Red X icons when using World Composition

UE - World Creation - Worldbuilding Tools - World Composition - Sep 20, 2018

This issue takes a few attempts to repro. Sometimes when saving the icons will remain normal, but other times a red X will be displayed instead. Opening up the Level that is displaying the X and re= ...

CharacterMovementComponent causes the Character to slide when jumping on moving objects

UE - Gameplay - Player Movement - Sep 21, 2018

When the CharacterMovementComponent makes the transition from falling to walking, it retains the forward velocity it had while falling. When the character lands on the moving object, its new velocit ...

When a client sends an Unreliable RPC to the Server in same frame with a Reliable RPC, Unreliable RPCs are Reliable

UE - Networking - Sep 25, 2018

When a client sends an Unreliable RPC to the Server in same frame with a Reliable RPC, Unreliable RPCs are Reliable. It implies extremely high lag on each lost RPC and all following ones. User lose ...

VR Trackpad Axis Values 0

UE - Platform - XR - Dec 16, 2019

Trackpad Values return 0 Additionally: I also observed that the Go's trigger is registering as Trigger MotionController (R) Facebutton 1  and that previously there were MotionController (R) Thumb ...

Open Formats: Interchange Import - UCX Convex Hull Import Bug

UE - Editor - Open File Formats - May 25, 2026

When importing custom UCX collision meshes from FBX files into Unreal Engine, certain geometry profiles fail to generate correctly if the option "One Convex Hull Per UCX" is unchecked. The engine's ...

Stationary Point Light is Visible After Building Lighting When Visible is Unchecked

UE - Graphics Features - Aug 30, 2016

While going through a blueprint tutorial which has you build a small structure with a point light in it, then have a script telling the point light to toggle on and off while entering a trigger. I n ...

SpeedTree Material No Longer Compiles With Texture Coordinate Node In BaseColor

UE - Graphics Features - Jan 25, 2017

If you open a material with the speedtree node plugged into WPO and then use a texture coordinate(index of 2) in base color the material will no longer compile properly. The full error is "Error [ ...

Materials Added to an FBX Will Not Be Added When Reimporting

Tools - Oct 25, 2018

Adding a material to an FBX with a Multi/Sub-object material, then reimporting the FBX will not import the new material. The material element will be added to the mesh but the material applied will ...

Translation Error during STEP import

UE - Editor - Content Pipeline - Datasmith - Importer - Mar 6, 2019

Using plugin version 4.21E3. The attached STEP file was generated using Fusion 360 v2.0.5357. It is a very basic house model. On import, the assembly named 'mod_Upper Hall2_v5_1' has several compone ...

Overriding a struct member field's default value on a BP-added component in a BP asset will no longer allow the user to edit that struct member on instances of that BP's component if the member is deprecated.

UE - Framework - Blueprint - Oct 19, 2023

Properties that are deprecated are (incorrectly) not currently being propagated to instances by the duplication logic that we use to instance BP-added components as part of Actor-based BP constructi ...